Textile size comprising an aqueous solution of urea and a poly alphaalkyl acrylic acid or a partial salt thereof



Patented July 21, 1953 TEXTILE SIZE COMPRISING AN AQUEOUS SOLUTION OF UREA AND A POLY ALPHA- ALKYL. ACRYLIC ACID OR A PARTIAL SAL THEREOF Walter M. Bruner and JamesC. Lhr, Wilmington, Del., assignors to E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation of. Delaware No Drawing. Application October 30, 1950,

' Serial No. 193,034

This invention relates to an improved textile size anda process for its use and, more particular- 1y, to a nylon textile size containing polymethacrylicacid and urea.

Heretofore textiles, prior to the weaving operations, have been sized with starch, gum, tallow, glu and like agents to improve appearance, feel and weaving characteristics. During the weaving, size compositions are used to protect the threads and may be removed by a desizing operation prior to or subsequent to further treatment of the textile. Higher efiiciency due to fewer loom stoppages and decrease in shedding on th loom during weaving are, inter alia, objectives of research in this field, which objectives'have not been met by the textile sizes of the art.

An object of the invention is to provide a superior and inexpensive textile size. Another object is to provide a textil 'size which improves the appearance and wearing qualities of treated cloth. A further object is to provide a size that may be readily desized from the woven-cloth prior to heat setting, leaving the cloth withan excellent color and hand. Yet another object is to provide a textile size containing as the essential ingredi- 9 Claims. (Cl. 260-295) 2 viscosity of 3,000 cp. at 25 C. when dissolved in water to the extent of 12% by weight. About 2% of the acid had been neutralized with sodium h-ydroxide. The size was made by dissolving 6-lb., oz. of crystal urea in gallons of water towhich was slowly added 13 lbs., 5 oz. of polymethacrylic acid containing the above amount of its sodium salt. The solution was agitated at room temperature during the addition and then'heated to 130 F. and held at that temperature for about 20 minutes to effect complete solution. This solution was then placed in a size-box in which the temperatur was maintained between and F. during the sizing of the nylon warp, the Warp being passed through the size box at a rate of 20 yards per minute. After sizing, the warp was squeezed to remove excess solution and then ents thereof a polymer of methacrylic acid and suitable means, applying to the surface of the material an aqueous solution containing polymethacrylic acid and urea. The invention may be carried out by passage of the textile material through an aqueous solution of the polymethacrylic acid and urea subsequent to whichthe excess sizing agent is removed by pressure and thereafter th water evaporated. By this process the material retains the size which permits weaving, knitting or other treatment in accord with the multiplicity'of operations normally used in the manufacture of textiles. Thereafter, if desired, the size can be removed com letely and with ease to leave thefinal product as' cloth, jersey or the like, with an excellent feel and appearance.

The invention may b more readily understood by consideration of the examplesin which parts arev by weight unless otherwise indicated.

Example 1.-Nyl0n warp, 532 yards long and 45 inches wide, having 5,400 ends, was slasher-sized with an aqueous solution containing 8% polymethacrylic acid and 4%.urea. The polymethacrylio acid used inpreparation of'the size had a dried by passing through 7 drying chambers maintainedrespectively at these temperatures," F.; 200 F.; 190 F.; 200 F.; 190 F.; 210 F'., and room temperature. Analysis of the warp showed that the pick up of the size varied between 2.03 and 2.30% by weight. The thus sized warp was placed in a C. and K. S6 automatic bobbin change loom and the warp woven continuously. Weaving efficiency was excellent and the-woven goods of first grade quality. A sample of the goods was heat set and then desized in a commercial desizing mill. Analysis of the desized goods showed 0.00% polymethacrylic acid and the goods had an excell nt hand.

Example 2.-Nylon taffeta was immersed in an aqueous solution containing 8% polymethacrylic acid, which had been. neutralized to the extent of about 2% with sodium hydroxide, and 4% urea, (a 12% by weight solution of the acid and salt in water had a viscosity of about 2,000 cp. at. 25 temperature) The sized tafieta was passed into the nip of two rubber wringer rolls to, give a 50% wet pick up. The sized taffeta was then air dried at room temperature and then suspended in an air circulating, oven for 15 seconds at 225 'C. Thereafter it was scoured, by washing with a solution of olive oil soap,a detergent and trisodium phosagent, had a good handandno noticeable discoloration.

Nylontaffeta was treated forcomparison with a size similartov that described above and by the process shown, except that sorbitol replaced the urea. This clothwas stifi and quite discolored.

(Nylon taffeta was also treated for comparison with a size similar to that described except that glycerine was used in:place of urea and-in this 3 operation also, the hand of the taffeta was slightly stifier than that of the urea treated tafieta and, moreover, there was some discoloration.

Example 3.Nylon tafieta was treated substantially in accord with the process described in Example 2, with 8% polymethacrylic acid and 4% urea in water, except that the polymethacrylic acid employed was not neutralized' (A 12% solution of this acid in water had a viscosity of to cp. at 25 C.) After sizing, drying in air at 225 0., followed by scouring, the cloth had a good hand and a very slight discoloration.

Nylon tafieta was similarly treated for comparison except that the urea was replaced by sorbitol. The cloth thus treated had a poor hand and was quite discolored. Another comparative treatment of nylon taffeta, in accord with the aforesaid process, was carried out except that glycerine replaced the urea. The product had a good hand but some discoloration.

In lieu of the polymethacrylic acid employed in the examples, other alpha-alkyl acrylic acid polymers may be employed, such, for example, as alpha-ethyl acrylic acid, alpha-propyl acrylic acid and the higher alpha-alkyl acrylic acids. The polymeric acid may be partially neutralized with a base to the extent of 15%, or a mixture of an alkali metal salt of the polymeric acid with the acid per se may be used, to give an equivalent mixture of polymeric acid and salt thereof. In sizing textiles generally, and nylon in particular, there should be present on the textile material in the order of at least 2% of either the polymeric acid per se or a mixture of acid and its salt. Such amounts ordinarily require the use of a bath containing a higher percentage of the polymeric acid, or mixture of acid and salt thereof, than desired on the textile material. Ordinarily not appreciably more than 50% pick up results from immersion and if the immersion method is employed, a concentration in the bath twice that desired on the filament should be used.

The sizing composition should contain from 2 to about 20% of the polymeric acid. If the size is sprayed on the textile material, substantially a 100% pick up, of course, will be obtained and a given solution of the polymeric acid can be made to give substantially the same concentration on the textile. The percentage of polymeric acid per se and/or partially neutralized, and more particularly polymethacrylic acid, on the textile material should range between 2 and 20% and specifically between 6 and 8%. With the acid and/ or salt there should be present urea to the extent of 50% by weight of the acid present, although this percentage may range between 25 to 55%. Pliability of the polymethacrylic acid is not appreciably influenced by urea present in amounts less than 20% and for optimum use, with relative humidity for the weaving or knitting at about 65%, the urea should be present to the extent of 40 to by weight of the polymethacrylic acid. Percentages above 50% may be employed but under such circumstances urea may crystallize out which is often undesirable and interferes, in some instances, with certain textile operations. The urea acts as a plasticizer for the polymethacrylic acid and likewise facilitates desizing of the textile either prior to heat setting or subsequent to that operation.

The textile materials that are sized by the compositions hereinbefore described may be derived from animal, synthetic or vegetable sources. The term textile materials when used herein is understood to include woven, knitted and material otherwise fabricated from fibers, threads, filaments, etc. of silk, artificial silks, such as rayon, cellulose acetate, cellulose acetobutyrate and the like, cotton, wool, rayon, linen, jute, etc. More particularly, however, the sizing compositions are most advantageously used with woven or knitted materials made from nylon or related polyamides.

Nylon is used in the specification and claims in accord with its well established meaning. The word is a generic term for any long-chain synthetic polymeric amide which has recurring amide groups as an integral part of the main polymer chain and which is capable of being formed into a filament in which the structural elements are oriented in the direction of the axis.

We claim:

1. A textile size comprising an aqueous solution containing from 2 to 20% by weight of a compound of the group consisting of a poly alphaalkyl acrylic acid, a partially neutralized poly alpha-alkyl acrylic acid and mixtures thereof and 25 to by weight of urea based on the weight of the polymeric compound of the group.

2. A textile size comprising an aqueous solution containing from 2 to 20% by weight of a poly methacrylic acid and 25 to 55% by weight of urea based on the weight of polymeric acid.

3. A textile size comprising an aqueous solution containing from 2 to 20% by weight of a poly alpha-alkyl acrylic acid partially neutralized with a base, and from 25 to 55% by weight of urea based on the weight of polymeric acid.

4. A textile size comprising an aqueous solution containing from 2 to 20% by weight of a polymethacrylic acid partially neutralized with an alkali metal, and 25 to 55% by weight of urea based on the weight of polymeric acid.

5. A textile size comprising an aqueous solution containing from 6 to 8% by weight of polymethacrylic acid and between 25 and 55% by weight of urea based on the weight of polymeric acid.

6. A textile size comprising an aqueous solution containing from 6 to 8% by weight of polymethacrylic acid and sodium polymethacrylate, and between 25 and 55% by weight of urea based on the weight of polymeric acid.

7. Textile materials of long chain synthetic polymeric carbonamides sized. with an aqueous solution containing 6 to 8% by weight of polymethacrylic acid and 25 to 55% by weight of urea based on the weight of the polymethacrylic acid.

8. A process for sizing textile materials which comprises passing said materials through an aqueous solution containing from 2 to 20% by weight of a poly alpha-alkyl acrylic acid and 25' to 55% by weight of urea based on the weight of polymeric acid.

9. A process for sizing long chain synthetic polymeric carbonamide textile materials which comprises passing said long chain synthetic polymeric carbonamide textile materials through an aqueous solution containing 6 to 8% by weight of polymethacrylic acid and 25 to 55% by weight of urea based on the weight of the polymethacrylic acid.

WALTER M. BRUNER. JAMES C. LEI-IR.

References Cited in the file of this patent UNITED STATES PATENTS Seymour et al. Sept. 18, 1945 

1. A TEXTILE COMPRISING AN AQUEOUS SOLUTION CONTAINING FROM 2 TO 20% BY WEIGHT OF A COMPOUND OF THE GROUP CONSISTING OF A POLY ALPHAALKYL ACRYLIC ACID, A PARTIALLY NEUTRALIZED POLY ALPHA-ALKYL ACRYLIC ACID AND MIXTURES THEREOF AND 25 TO 55% BY WEIGHT OF UREA BASED ON THE WEIGHT OF THE POLYMERIC COMPOUND OF THE GROUP. 